Fill background problem

I created this actionscripts but the problem is that when I click the bt1 (button 1) the function does not runs completely … I know that I am doing something wrong but I don’t know what.

Tile (image)is the linkage of one of the patterns and office is another image.
bckg is a movieclip that for some reason I had to create to be able to see the buttons.
I create three buttons in the first layer, and in the second layer I only put this actions on the frame.

Here is the Actionscript:


Stage_w = Stage.width;
Stage_h = Stage.height;
/// class imported ///

import flash.display.BitmapData;
import flash.geom.Point;

var tile = BitmapData.loadBitmap(“tile”);

var office:BitmapData = BitmapData.loadBitmap(“office”);

function fillBG() {
this.moveTo(0, 0);
this.lineTo(Stage_w, 0);
this.lineTo(Stage_w, Stage_h);
this.lineTo(0, Stage_h);
this.lineTo(0, 0);


var nextNum:Number = 0;

bt1.onRelease = function():Void{
nextNum = tile.pixelDissolve(office, tile.rectangle, point,nextNum,5000,0x000000);